1. Technical Field
The technologies disclosed herein relate to a camera body, a camera system, and an interchangeable lens unit comprising an imaging sensor for performing opto-electric conversion.
2. Description of the Related Art
Digital cameras, with which an imaging sensor such as a CCD (charge coupled device) imaging sensor or a CMOS (complementary metal-oxide semiconductor) imaging sensor is used to convert a subject image into an electrical signal, have rapidly grown in popularity in recent years.
In a compact digital camera, a lens unit and a camera body having an imaging sensor are integrated. Convenience is important with compact digital cameras, and they are capable not only of still picture imaging, but also moving picture imaging.
On the other hand, high performance is more important with an interchangeable lens type of camera system. More specifically, an interchangeable lens unit can be mounted to and removed from a camera body. A number of interchangeable lens units of various performance are readied and used as dictated by the situation. The user can replace these interchangeable lens units on the camera body in taking pictures.
In the interchangeable lens type of camera systems widely available on the market, an imaging sensor is provided to the camera body. The interchangeable lens unit guides an optical image of the subject to the imaging sensor of the camera body. That is, the interchangeable lens unit has no imaging sensor.
Meanwhile, Japanese Laid-Open Patent Application 2000-175089 discloses a camera system made up of an interchangeable lens unit having an imaging sensor, and a camera body that does not have an imaging sensor.
Also, Japanese Laid-Open Patent Application 2006-254088 discloses a camera system made up of an interchangeable lens unit that has an imaging sensor, and a camera body that also has an imaging sensor. With this camera system, the imaging sensor of the camera body is also equipped with a lens for forming an optical image. The camera body is able to capture images even when no interchangeable lens unit has been mounted.